Muscle cardboard = heavy-duty cardboard (reinforced cardboard) This material was created in the United States in the 1950s and has a proven track record as a packaging material that replaces wooden boxes .

Of course, we also provide wooden boxes for packing heavy items. It is used all over the world as a material for wooden pallets, furniture, temporary facilities, etc., thanks to its high load-bearing capacity and high strength, making it an attractive alternative to wood, steel, aluminum, and plastic.

It is an excellent material that can be used to pack heavy and delicate items such as engines, semiconductors, and other precision mechanical parts, as well as liquids and powders .

Regular cardboard is made from recycled paper, Muscle cardboard = heavy-duty cardboard (reinforced cardboard) is made primarily from virgin pulp , and its longer-than-normal fibers are the secret to its strength.

It has a rough texture that allows you to feel the long fibers of the pulp, but it also has the soft fuzz of the fibers and the warmth of the paper, giving it a rich, textured feel that is distinctive to the touch.

In addition, the surface is not coated with varnish or other coatings and is unbleached, making it an environmentally friendly, pure material .

Components from the remaining trees react to ultraviolet rays from fluorescent lights and direct sunlight, causing discoloration due to sunburn (turning red temporarily and slowly changing to a yellowish brown over the course of several years), but these are all characteristics unique to paper made using whole natural materials.

The safety of this material has been recognized by the FDA (Food and Drug Administration) as being "safe to come into contact with food."

It has also been certified for food packaging use, so it can be used safely even in homes with small children.